>AFAIK, it's still the case that one can create RDF graphs for which
>there is no XML-RDF representation; If so, that seems a pretty fatal
>flaw in a syntax.
It looks as though it's well on its way to being fixed :
"
- add an attribute rdf:node to the RDF/XML syntax.
- modify the syntax to permit rdf:node in place of rdf:about.
- such a use associates the value of the attribute as a file scoped
identifier for the blank node
..."
http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Jul/0080.html